The application of adhesives to floor substrates, for example for the purpose of laying carpet to undercushion, ceramic tiles, linoleum and vinyl tile normally necessitates manual application of an adhesive by a person kneeling on his or her knees. Prolonged kneeling and bending, especially by tradespeople over many years, results in knee and back problems and disabilities.
Applicators are known for applying adhesives to a floor substrate. U.S. Pat. No. 4,798,163, for example, discloses the use of a device for applying a liquid adhesive, in particular hot melt adhesive. The device comprises a reservoir, a separate application nozzle, and a shutoff valve in a line from the reservoir to the nozzle. This patent particularly relates to an improved nozzle for administering hot melt adhesive. The apparatus contains a melting means for the hot melt adhesive to reduce the pressure required to pump the hot melt adhesive through the nozzle to the substrate.
U.S. Pat. No. 4,919,072 discloses an apparatus for applying a hot melt adhesive to a substrate. The apparatus includes a heating means for heating the hot melt adhesive and an electrical control means for regulating the heating means. An application head applies the hot melt adhesive to the substrate either as a thin uniform layer or as a spray. The electrical control means is detachable from the apparatus.